Abstract: The inspection system of the CPC (Communist Party of China) is an important system of supervision within the Party. This system has been innovated and reformed since the 18th National Congress of the CPC. Through a review of the evolution of the inspection system within the Party, this paper shows that the development of the inspection system has a distinct phase characteristic; the inspection system has shown continuity and innovation after the 18th National Congress of the CPC. On the basis of its original system, the inspection system has continuously innovated on the mythos, position, way, methods, and employment mechanism. The effectiveness of the inspection system highlights the dual logical aspects of internal and external factors: as for the internal factors, the central government has attached great importance to inspections to reflect the key role of internal factors since the 18th National Congress of the CPC; as for the external factors, the inspection system becomes more progressive and standardized, the composition of inspector has become more reasonable, and the literacy is constantly improved, which demonstrate the promoting role of external factors.